One frequently-asked question on PIPORG-L (the Internet mailing list for pipe organ matters) is how to build a MIDI-based pedalboard, or how to equip an existing pedalboard with MIDI. Usually, the purpose is to provide a pedalboard that can be used with one or more electronic keyboards for home or practice use.

I built myself a 27-note flat parallel pedalboard with a MIDI interface to use with my Yamaha Clavinova. The pedalboard is almost BDO standard, the difference being that the keys are 100 mm shorter than standard for space reasons. This makes playing slightly more difficult but not impossibly so - skilled organists (a category that does not include me) have had no difficulty playing it.

I built the pedalboard from maple, which the village carpenter procured and cut roughly to size. As a constructional project, it proved quite easy to build, requiring only moderate wood-working skills. I was unable to find proper springs to fit at the heel end of the pedals and initially had to use coil springs under the pedal toes. These were not very satisfactory since they tended to creak slightly and were too strong. I later found that proper flat springs are available from Organ Supply Industries in the USA and Laukhuff in Germany (addresses below) and fitted these in place of the coil springs, with much improved results.


This drawing shows how the pedals are sprung at the heel end. The plate spring is screwed to the underside of the pedal and rests on a steel rod running across the width of the heel block. When the adjusting screw is tightened, it tenses the spring, holding the toe of the pedal up against the toe board buffer. The weight of the touch can be adjusted by tightening or loosening the adjusting screw.

For the MIDI interface, I used a small keyboard scanning module available from Maplin in the UK. This unit is no longer available but I have found a supplier of a much more versatile unit, Sound Research in California. Unlike the Maplin unit, this is assembled (but you still need to provide a box and power supply for it). The unit can be programmed easily to output on any MIDI channel and several other configuration options are available too. I found it worked perfectly and added versatility to my system.

The MIDI encoder requires that each key be fitted with a switch. I first fitted my pedalboard with micro-switches, but these proved too noisy and difficult to adjust. I then changed these for reed switches, operated by tiny magnets on the pedal toes. Both switches and magnets are mounted vertically such that the magnet causes the switch to operate just before the pedal reaches the end of its travel.


This drawing shows the pedal in its 'up' (released) position. When the pedal is depressed, a magnet glued vertically to the toe end of the pedal is brought alongside the reed switch, fixed vertically to a wooden block, causing it to close. The reed switch is held to the block by its contact wires. The block is mounted on a metal bracket and can be moved closer to or away from the pedal to adjust the moment at which the reed switch closes (see the photos below).

The system now works perfectly, apart from one occasion when a magnet came unglued and stuck to the reed switch, holding the switch on and causing a MIDI cipher!

I originally used the pedalboard and the Clavinova together with a Roland MT-32 sound box. With the Clavinova set to transmit on MIDI channel 1 and the pedalboard transmitting on channel 2, this gave one voice for the manual and a different one for the pedal. I now use a piece of software called Hauptwerk, which contains digitized samples of each pipe in a real pipe organ and is infinitely better than the Roland sound box. It does require a fast computer with plenty of memory and, obviously, a MIDI interface. A wide variety of USB/MIDI interfaces are available - I use the M-Audio USB Midisport 4x4, which provides 4 MIDI in and 4 MIDI out connections.

Hauptwerk is shareware - you can download it and try it for free before purchasing it (at a very reasonable price) and several organs are available both from the author of Hauptwerk and from other sources.

So, with my MIDI keyboard and pedalboard, USB/MIDI interface, extra memory for the computer (1.5 Gbytes is recommended to get the best out of Hauptwerk but my machine can only take 1 Gbyte, which is satisfactory but not ideal), plus some decent speakers, I have a reasonable, low-cost (well, cheaper than a real pipe organ) practice system. The limitation now is the single manual - Sound Research sells a two-manual MIDI set...

BDO standard, 27 notes, flat, parallel keys. Built of maple, with sharps and heel board stained cherry, treated with three coats of clear marine varnish. Weight approx. 35 kg.

Addresses

The Hauptwerk software is available at:


	http://www.hauptwerk.co.uk/

The MIDI scanner module is available from:


	Sound Research

	177 Old Oak Road

	Newcastle

	CA 95658

	USA



	Phone:	(+1) 916 663 9432

	E-mail: SoundResearch@Sound-Research.net

	WWW:	http://www.sound-research.net

The module reference is: PED MUX 25/32. See the Sound Research Web page for full technical details and latest prices.

Flat pedal springs are available from:


	Organ Supply Industries Inc

	PO Box 8325

	Erie, PA 16505-0325

	USA



	Phone: 814 835 2244

	Fax:   814 838 0349

Ref
Size (length x width x thickness)
(inches)
0350.01
4 x 7/8 x 1/8

Minimum quantity: 100

or:

	Aug. Laukhuff Orgelteile

	Postfach 1133

	D 97984 Weikersheim

	Germany



	Phone:  (+49) 79 34 611

	Fax:    (+49) 79 34 616

	E-mail: laukhufforgel@t-online.de

Ref
Size (length x width x thickness)
(mm)
1 845 00
1 845 01
1 845 02
 90 x 22 x 1.75
105 x 22 x 1.75 (the ones I used)
120 x 22 x 1.75

Minimum quantity: 100

Since prices change, you should contact the vendors directly for current prices before you order.


This close-up shows a rear view of the wooden blocks supporting the reed switches. The magnets mounted vertically on the pedal toes can be seen behind the blocks.
 
These 25-pin computer connectors link the pedalboard to the control box containing the MIDI scanning module.